ar X iv : a st ro - p h / 01 07 49 1 v 1 2 5 Ju l 2 00 1 Globular Cluster Population of Hickson Compact Group 22 a and 90 c 1
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چکیده
We present the first measurement of the globular cluster populations of galaxies in Hickson compact groups, in order to investigate the effect of these high density environments on the formation and evolution of globular cluster systems. Based on V and R band images that we obtained of HCG 22a and HCG 90c with the ESO New Technology Telescope (NTT), we find a total globular cluster population of 1590± 854 for HCG 22a and 2136± 718 for 90c. The specific frequency for HCG 22a was found to be SN = 1.9 ± 1.0 and SN = 3.4 ± 1.1 for HCG 90c. A power-law fit to the globular cluster radial profile of HCG 22a yields σ ∼ R and for HCG 90c we found σ ∼ R. A comparison of the globular cluster radial profiles with the surface brightness of the parent galaxy shows that the globular cluster systems are at least as extended as the halo light. The measured values for the specific frequency are consistent with a scenario in which the host galaxies were in a low density “field-like” environment when they formed their globular cluster systems. Subject headings: galaxies: compact groups—galaxies: individual (NGC 1199, NGC 7173)—globular
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تاریخ انتشار 2001